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(No Model.)

ATTORNEY T. A. EDISON, INGANDESGING ELECTRIC LAMP. No. 358,600. Patented Mar. 1,1887.

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BY 1S 0am- @V/M UNITED STATES PATn T tries.

THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY, ASSIGNOR TO THE EDISON ELECTRIC LIGHT COMPANY, OF NEW YORK, N. Y.

INCANDESCING ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent l \To. 358,600, dated March 1, 1857 Application filed August 7, I882. Serial No. 68.610. (N0 model.)

To all whom it may concern.-

Be it known that I, THOMAS A. EDISON, of Menlo Park, in the county of Middlesex and State of New Jersey, have invented a new and useful Improvement in Incandescing Electric Lamps, (Case No. 386;) and I do hereby declare that the following is a full and exact description of the same, reference being bad to the accompanying drawing, and to the letters of reference marked thereon.

The object I have in view is to produce another way of constructing carbon filaments of high resistance forincandescing electrielamps. This I accomplish by securing together by electroplated joints a number of carbon filaments, the end filaments being electroplated to the leadingin wires of the lamp.

In carrying out my invention I preferably take a natural fibersueh as a wood fiberand cut into straight pieces or filaments with enlarged ends. These straight filaments are then carbonized without being bent. A number of the straight carbon filaments are then placed parallel with each other, and are secured to gether, end to end, by mechanical unious--as, for instance, by wrapping with fine wire or with metal foil. These unions are then elce troplated, the carbon filaments being kept separated by tissue-paper or other suitable material. After electroplating, the connected carbon filaments are sprung apart, so that they assume a zigzag form, and the end filaments are first mechanically secured to the leading in wires and then electroplated thereto.

The drawing shows the glass wire-support of the ineandescing electric lamp, the leadingin wires, and the carbon in elevation.

A represents the glass wire-support, in the upper part of which the leading-in wires 1 2 are sealed.

0 is the incaudcscing carbon conductor of the lamp, composed of straight carbon filaments 0 to 0 inclusive. These filaments hzwe enlarged ends (I, which are secured together by electroplated unions, the lower ends oi the outer filaments, 0 0 being electroplated to the leading-in wires.

It is evident that any number of straight carbon filaments (four or more) can be secured together in this way to secure the desired high resistance and form the zigzag carbon.

What I claim is 1. An incandcscing conductor for an electric lamp, composed of two or more carbon filaments joined together by electroplating, substantially as set forth.

2. The combination, in an electric lamp, of two or more carbon filaments joined together by electroplating, and leading-in wires eon nected with such carbon filaments by electroplated joints, substantially as set forth.

3. The zigzag incandesciug conductor for an electric lamp, composed of a number of sepa rate straight carbon filaments joined together at their ends by electroplating, substantially as set forth.

This specification signed and witnessed this 13th day of December, 1881.

THOS. A EDISON.

Witnesses:

RIoHD. N. DYER, H. W. SEELY. 

